forked from badman12345/osmose-rpi
/
VDP.cpp
900 lines (798 loc) · 26.9 KB
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VDP.cpp
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/*****************************************************************************
*
* File: VDP.cpp
*
* Project: Osmose emulator.
*
* Description: This class will handle VDP (Video Display Processor)operation.
*
* Author: Vedder Bruno
* Date: 11/10/2004, 08h30
*
* URL: http://bcz.emu-france.com/
*****************************************************************************/
#include "VDP.h"
extern Options opt;
// Pre calculated Vertical count values, for 192 line NTSC video.
unsigned char vcount_ntsc_192[262] =
{
0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0A, 0x0B, 0x0C, 0x0D, 0x0E, 0x0F,
0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17, 0x18, 0x19, 0x1A, 0x1B, 0x1C, 0x1D, 0x1E, 0x1F,
0x20, 0x21, 0x22, 0x23, 0x24, 0x25, 0x26, 0x27, 0x28, 0x29, 0x2A, 0x2B, 0x2C, 0x2D, 0x2E, 0x2F,
0x30, 0x31, 0x32, 0x33, 0x34, 0x35, 0x36, 0x37, 0x38, 0x39, 0x3A, 0x3B, 0x3C, 0x3D, 0x3E, 0x3F,
0x40, 0x41, 0x42, 0x43, 0x44, 0x45, 0x46, 0x47, 0x48, 0x49, 0x4A, 0x4B, 0x4C, 0x4D, 0x4E, 0x4F,
0x50, 0x51, 0x52, 0x53, 0x54, 0x55, 0x56, 0x57, 0x58, 0x59, 0x5A, 0x5B, 0x5C, 0x5D, 0x5E, 0x5F,
0x60, 0x61, 0x62, 0x63, 0x64, 0x65, 0x66, 0x67, 0x68, 0x69, 0x6A, 0x6B, 0x6C, 0x6D, 0x6E, 0x6F,
0x70, 0x71, 0x72, 0x73, 0x74, 0x75, 0x76, 0x77, 0x78, 0x79, 0x7A, 0x7B, 0x7C, 0x7D, 0x7E, 0x7F,
0x80, 0x81, 0x82, 0x83, 0x84, 0x85, 0x86, 0x87, 0x88, 0x89, 0x8A, 0x8B, 0x8C, 0x8D, 0x8E, 0x8F,
0x90, 0x91, 0x92, 0x93, 0x94, 0x95, 0x96, 0x97, 0x98, 0x99, 0x9A, 0x9B, 0x9C, 0x9D, 0x9E, 0x9F,
0xA0, 0xA1, 0xA2, 0xA3, 0xA4, 0xA5, 0xA6, 0xA7, 0xA8, 0xA9, 0xAA, 0xAB, 0xAC, 0xAD, 0xAE, 0xAF,
0xB0, 0xB1, 0xB2, 0xB3, 0xB4, 0xB5, 0xB6, 0xB7, 0xB8, 0xB9, 0xBA, 0xBB, 0xBC, 0xBD, 0xBE, 0xBF,
0xC0, 0xC1, 0xC2, 0xC3, 0xC4, 0xC5, 0xC6, 0xC7, 0xC8, 0xC9, 0xCA, 0xCB, 0xCC, 0xCD, 0xCE, 0xCF,
0xD0, 0xD1, 0xD2, 0xD3, 0xD4, 0xD5, 0xD6, 0xD7, 0xD8, 0xD9, 0xDA, 0xD5, 0xD6, 0xD7, 0xD8, 0xD9,
0xDA, 0xDB, 0xDC, 0xDD, 0xDE, 0xDF, 0xE0, 0xE1, 0xE2, 0xE3, 0xE4, 0xE5, 0xE6, 0xE7, 0xE8, 0xE9,
0xEA, 0xEB, 0xEC, 0xED, 0xEE, 0xEF, 0xF0, 0xF1, 0xF2, 0xF3, 0xF4, 0xF5, 0xF6, 0xF7, 0xF8, 0xF9,
0xFA, 0xFB, 0xFC, 0xFD, 0xFE, 0xFF
};
// Pre calculated Vertical count values, for 192 line NTSC video.
unsigned char vcount_palsecam_192[313] = {
0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0A, 0x0B, 0x0C, 0x0D, 0x0E, 0x0F,
0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17, 0x18, 0x19, 0x1A, 0x1B, 0x1C, 0x1D, 0x1E, 0x1F,
0x20, 0x21, 0x22, 0x23, 0x24, 0x25, 0x26, 0x27, 0x28, 0x29, 0x2A, 0x2B, 0x2C, 0x2D, 0x2E, 0x2F,
0x30, 0x31, 0x32, 0x33, 0x34, 0x35, 0x36, 0x37, 0x38, 0x39, 0x3A, 0x3B, 0x3C, 0x3D, 0x3E, 0x3F,
0x40, 0x41, 0x42, 0x43, 0x44, 0x45, 0x46, 0x47, 0x48, 0x49, 0x4A, 0x4B, 0x4C, 0x4D, 0x4E, 0x4F,
0x50, 0x51, 0x52, 0x53, 0x54, 0x55, 0x56, 0x57, 0x58, 0x59, 0x5A, 0x5B, 0x5C, 0x5D, 0x5E, 0x5F,
0x60, 0x61, 0x62, 0x63, 0x64, 0x65, 0x66, 0x67, 0x68, 0x69, 0x6A, 0x6B, 0x6C, 0x6D, 0x6E, 0x6F,
0x70, 0x71, 0x72, 0x73, 0x74, 0x75, 0x76, 0x77, 0x78, 0x79, 0x7A, 0x7B, 0x7C, 0x7D, 0x7E, 0x7F,
0x80, 0x81, 0x82, 0x83, 0x84, 0x85, 0x86, 0x87, 0x88, 0x89, 0x8A, 0x8B, 0x8C, 0x8D, 0x8E, 0x8F,
0x90, 0x91, 0x92, 0x93, 0x94, 0x95, 0x96, 0x97, 0x98, 0x99, 0x9A, 0x9B, 0x9C, 0x9D, 0x9E, 0x9F,
0xA0, 0xA1, 0xA2, 0xA3, 0xA4, 0xA5, 0xA6, 0xA7, 0xA8, 0xA9, 0xAA, 0xAB, 0xAC, 0xAD, 0xAE, 0xAF,
0xB0, 0xB1, 0xB2, 0xB3, 0xB4, 0xB5, 0xB6, 0xB7, 0xB8, 0xB9, 0xBA, 0xBB, 0xBC, 0xBD, 0xBE, 0xBF,
0xC0, 0xC1, 0xC2, 0xC3, 0xC4, 0xC5, 0xC6, 0xC7, 0xC8, 0xC9, 0xCA, 0xCB, 0xCC, 0xCD, 0xCE, 0xCF,
0xD0, 0xD1, 0xD2, 0xD3, 0xD4, 0xD5, 0xD6, 0xD7, 0xD8, 0xD9, 0xDA, 0xDB, 0xDC, 0xDD, 0xDE, 0xDF,
0xE0, 0xE1, 0xE2, 0xE3, 0xE4, 0xE5, 0xE6, 0xE7, 0xE8, 0xE9, 0xEA, 0xEB, 0xEC, 0xED, 0xEE, 0xEF,
0xF0, 0xF1, 0xF2, 0xBA, 0xBB, 0xBC, 0xBD, 0xBE, 0xBF, 0xC0, 0xC1, 0xC2, 0xC3, 0xC4, 0xC5, 0xC6,
0xC7, 0xC8, 0xC9, 0xCA, 0xCB, 0xCC, 0xCD, 0xCE, 0xCF, 0xD0, 0xD1, 0xD2, 0xD3, 0xD4, 0xD5, 0xD6,
0xD7, 0xD8, 0xD9, 0xDA, 0xDB, 0xDC, 0xDD, 0xDE, 0xDF, 0xE0, 0xE1, 0xE2, 0xE3, 0xE4, 0xE5, 0xE6,
0xE7, 0xE8, 0xE9, 0xEA, 0xEB, 0xEC, 0xED, 0xEE, 0xEF, 0xF0, 0xF1, 0xF2, 0xF3, 0xF4, 0xF5, 0xF6,
0xF7, 0xF8, 0xF9, 0xFA, 0xFB, 0xFC, 0xFD, 0xFE, 0xFF
};
/* Constructor */
VDP::VDP(Z80 *c, bool ntsc)
{
cpu = c;
VRAM = new unsigned char[0x4000];
CRAM = new unsigned char[64];
colors = new unsigned short[64];
// Select appropriate vcount array, depending on ntsc/pal option.
if (ntsc == true)
{
v_cnt = vcount_ntsc_192;
}
else
{
v_cnt = vcount_palsecam_192;
}
if ((VRAM !=NULL) && (CRAM !=NULL))
{
for(int i=0; i < 64; i++)
{
CRAM[i] = 0x0;
}
for(int i=0; i < 0x4000; i++)
{
VRAM[i] = 0x0;
}
reset();
}
else
{
cerr << "Unable to allocate memory for ROM banks !" << endl;
cerr << "Exiting." << endl;
exit(-1);
}
}
/*-------------------------------------------------------------*/
/* This method handles write operation on the VDP data port. */
/*-------------------------------------------------------------*/
void VDP::writeDataPort(unsigned char data) /* Port 0xBE written */
{
cmd_flag = false;
rd_data_port_buffer = data; // CMD docs says that write, load buffer with it's value.
// destination is VRAM or CRAM ?
if (cmd_type == 3)
{
CRAM[addr & 0x1F] = data; // data not anded with 1f. It's done with rgb rate.
#ifdef VDP_VERBOSE
cout << "CRAM written: at 0x" << hex << setw(4) << setfill('0')<< addr << " with value "<< setw(2) << setfill('0') << (int)data <<endl;
#endif
colors[addr & 0x1f] = colorSMS8BitsToColor16Bits( data);
addr++;
addr &=0x3FFF;
}
else // Destination is VRAM
{
VRAM[addr] = data;
#ifdef VDP_VERBOSE
cout << "VRAM written: at 0x" << hex << setw(4) << setfill('0')<< addr << " with value "<< setw(2) << setfill('0') <<(int)data <<endl;
#endif
addr++;
addr &=0x3FFF;
}
}
/*---------------------------------------------------------------*/
/* This method convert 8bit xxRRGGBB to RRRRRGGGGGGBBBBB colors .*/
/*---------------------------------------------------------------*/
unsigned short VDP::colorSMS8BitsToColor16Bits(unsigned char data)
{
unsigned char r, g, b;
r = r_col[(data & 3)];
g = g_col[(data >> 2) &3];
b = b_col[(data >> 4) &3];
return (unsigned short)(r << 11) | (g <<5) | (b);
}
/*---------------------------------------------------------------*/
/* This method convert 8bit xxRRGGBB to RRRRRGGGGGGBBBBB colors .*/
/*---------------------------------------------------------------*/
unsigned short VDP::colorGG12BitsToColor16Bits(unsigned short data)
{
unsigned char r, g, b;
r = (data & 0xF) << 1;
g = ((data >> 4) & 0xF)<<2;
b = ((data >> 8) & 0xF)<<1;
return (unsigned short)(r << 11) | (g <<5) | (b);
}
/*-------------------------------------------------------------*/
/* This method handles read operation on the VDP data port. */
/*-------------------------------------------------------------*/
unsigned char VDP::readDataPort() /* Port 0xBE read */
{
unsigned char r;
cmd_flag = false;
r = rd_data_port_buffer;
#ifdef VDP_VERBOSE
cout << "VRAM read: at 0x" << hex << setw(4) << setfill('0')<< addr << " value = "<< setw(2) << setfill('0') <<(int)r <<endl;
#endif
rd_data_port_buffer = VRAM[addr];
addr++;
addr &= 0x3FFF;
return r;
}
/*-------------------------------------------------------------*/
/* This method handles write operation on the VDP control port.*/
/* This port is at 0xBF */
/*-------------------------------------------------------------*/
void VDP::writeCtrlPort(unsigned char data) /* Port 0xBF/0xBD written */
{
if (cmd_flag == false)
{
cmd_flag = true; /* We receive first byte of command word */
latch = data;
}
else
{
cmd_flag = false; /* We receive second byte of command word */
cmd_type = data >> 6; /* 2second byte MSB are cmd type */
addr = ( (data & 0x3F ) << 8) | latch;
if (cmd_type == 0)
{
rd_data_port_buffer = VRAM[addr];
addr = (addr +1) & 0x3FFF;
}
if (cmd_type == 2) // Cmd: 10 VDP register write */
{
writeRegs(data & 0xF, latch);
}
#ifdef VDP_VERBOSE
switch (cmd_type)
{
case 0:
cout << "VRAM read: VDP Addr set to 0x" << hex << setw(4) << setfill('0')<< addr << endl;
break;
case 1:
cout << "VRAM write: VDP Addr set to 0x" << hex << setw(4) << setfill('0')<< addr << endl;
break;
case 2:
cout << "REG write: VDP Regs " << (int)(data & 0xF) << " written with value "<< hex << setw(2) << setfill('0')<<(int)latch << endl;
break;
case 3:
cout << "CRAM write: Addr in palete is " << hex << setw(4) << setfill('0')<<(int)addr << endl;
break;
}
#endif
}
}
/*------------------------------------------------------------*/
/* Call back when port BF/BD is read. */
/*------------------------------------------------------------*/
unsigned char VDP::readStatusFlag()
{
unsigned char tmp;
cmd_flag = false; // this flag is cleared when Ctrl port is read.
tmp = vdp_status;
vdp_status &= 0x1f; // Clear bit 6 & 7 from vdp_status.
irq_line_pending = false;
vsynch_irq_pending = false;
updateIRQAssertion();
return tmp;
}
/*------------------------------------------------------------*/
/* This method return VDP RAM internal pointer. */
/*------------------------------------------------------------*/
unsigned short VDP::getVRAMAddr()
{
return addr;
}
/*------------------------------------------------------------*/
/* This method will reset the VDP by setting latch / regs */
/* to Zero, supposing it's the thing to do ! */
/*------------------------------------------------------------*/
void VDP::reset()
{
addr = 0;
latch = 0;
cmd_flag = false;
v_counter = 0;
i_counter = 0xFF;
vdp_status= 0x1f; // 00011111b
line = 0;
sms_irq = false;
irq_line_pending = false;
vsynch_irq_pending = false;
cmd_type = 0;
rd_data_port_buffer = 0;
if (emu_opt.bright_palette == true)
{
r_col[0] = 0;
r_col[1] = 10;
r_col[2] = 21;
r_col[3] = 31;
g_col[0] = 0;
g_col[1] = 21;
g_col[2] = 42;
g_col[3] = 63;
b_col[0] = 0;
b_col[1] = 10;
b_col[2] = 21;
b_col[3] = 31;
}
else
{
r_col[0] = 0;
r_col[1] = 8;
r_col[2] = 16;
r_col[3] = 24;
g_col[0] = 0;
g_col[1] = 16;
g_col[2] = 32;
g_col[3] = 48;
b_col[0] = 0;
b_col[1] = 8;
b_col[2] = 16;
b_col[3] = 24;
}
for (int i=0; i<VDP_REGISTER_NBR; i++)
{
regs[i] = 0;
}
REG2 = 0xE; /* xxxx111x -> map default to 0x3800 in VRAM */
map_addr = 0x3800; /* REG2 converted into VRAM address. */
REG5 = 0x7E; /* x111111x -> sit default to 0x3F00 in VRAM */
sit_addr = 0x3F00; /* REG5 converted into VRAM address. */
REG10 = 0xFF; /* No Line Interrupt */
#ifdef BUILT_IN_DEBUGGER
irq_accepted = false;
#endif
}
/*------------------------------------------------------------*/
/* This is a debugging purpose function. */
/* Note that this method will dump VDP VRAM. */
/*------------------------------------------------------------*/
void VDP::dumpVRAM(unsigned int sa, int nb_lines)
{
cout << "Dumping VDP RAM:"<<endl;
sa &=0x3fff;
for (int i=0; i<nb_lines; i++)
{
cout << hex << setw(4) << setfill('0') << (i*16+sa) << ": ";
for (int o=0;o<16;o++)
{
cout << hex << setw(2) << setfill('0') <<(int) VRAM[sa++] << " ";
sa &= 0x3FFF;
}
cout << endl;
}
}
/*------------------------------------------------------------*/
/* This is a debugging purpose function. */
/* Note that this method will dump VDP CRAM. */
/*------------------------------------------------------------*/
void VDP::dumpCRAM()
{
int ind = 0;
cout << "Dumping VDP CRAM:"<< endl;
for (int i=0; i<4; i++)
{
cout << hex << setw(4) << setfill('0') << (i*16) << ": ";
for (int o=0;o<16;o++)
{
cout << hex << setw(2) << setfill('0') <<(int) CRAM[ind++] << " ";
}
cout << endl;
}
}
/*------------------------------------------------------------*/
/* This method is called on each VDP register write. Parameter*/
/* is the index of the register in reg array. */
/*------------------------------------------------------------*/
void VDP::writeRegs(unsigned char r,unsigned char v)
{
regs[r] = v;
switch (r)
{
case 0:
/* Change IRQ assertion if Line IRQ are enabled/disabled.*/
updateIRQAssertion();
break;
case 1:
/* Change IRQ assertion if VSYNC IRQ are enabled/disabled.*/
updateIRQAssertion();
break;
case 2:
map_addr = (REG2 & 0xE) << 10; /* 0xE = 00001110b. */
break;
case 5:
sit_addr = (((REG5 >> 1) & 0x3F) << 8 );
break;
}
#ifdef VDP_VERBOSE
if (r == 2 || r==5)
{
cout << "VDP REGISTER: tile map address set to 0x" << hex << setw(4) << setfill('0') << map_addr << endl;
cout << "VDP REGISTER: sprite information table set to 0x" << hex << setw(4) << setfill('0') << sit_addr << endl;
}
#endif
}
/*------------------------------------------------------------*/
/* This method is called when a scanline has been drawn. */
/* It draws one line in screen. Set sms_irq if VDP triggers */
/* an interrupt. */
/* If drawline is true, line render is done else it's skipped */
/* This is for frame skip, to handle interrupt system, but to */
/* avoid drawing line if frame is not displayed. */
/*------------------------------------------------------------*/
void VDP::update(SDL_Surface *s, bool drawline)
{
if (line < 0xC0)
{
if (drawline == true)
{
SDL_LockSurface(s);
traceBackGroundLine(s);
SDL_UnlockSurface(s);
}
}
/* V-Blank interrupt. */
if (line == 0xC1)
{
vdp_status |= BIT7;
vsynch_irq_pending = true;
}
/* Line interrupt. */
if (line < 193)
{
i_counter--;
/* Line counter overflow. */
if (i_counter == 0xFF)
{
i_counter = REG10;
irq_line_pending = true;
}
}
else i_counter = REG10;
updateIRQAssertion();
v_counter = v_cnt[line];
#ifdef BUILT_IN_DEBUGGER
/*
This event is thrown on every scanline. The dedbugger will react depending
on the scanline break point.
*/
throwDebugEvent(DbgEvtScanlineBreakpoint,"VDP", "End of current Scanline.");
#endif
}
/*------------------------------------------------------------*/
/* This method update sms_irq value depending on VDP registers*/
/* and interrupt pending. */
/*------------------------------------------------------------*/
void VDP::updateIRQAssertion()
{
sms_irq = false;
if (irq_line_pending && (REG0 & BIT4))
{
sms_irq = true;
//cout << "IRQ from Line IRQ " << dec <<line << endl;
}
if (vsynch_irq_pending && (REG1 & BIT5))
{
sms_irq = true;
//cout << "IRQ from Line VSYNCH " << dec <<line << endl;
}
if (sms_irq)
{
if (opt.irq_hack) cpu->step();
cpu->interrupt( 0xFF );
}
}
/*--------------------------------------------------------------*/
/* This method draws a scanline. */
/* */
/* Drawing is done in two pass: */
/* - Render tile background */
/* (sprite are rendered, then) */
/* - Render tile that cover sprites */
/*--------------------------------------------------------------*/
void VDP::traceBackGroundLine(SDL_Surface *s)
{
unsigned int c,pos;
unsigned short *dst;
unsigned short *scr;
unsigned short currentTile;
unsigned char i, o, x, y, col_index, attrib;
int current_line;
unsigned int p;
/* scr ptr in our SDL_Surface points line to be drawn. */
scr = (unsigned short*) s->pixels + (256 * line);
/* Draw a blank line directly in screen if display is disabled. */
if (!(REG1 & BIT6))
{
memset(scr,0x0, 0x200); // 0x200 means 256 16bits pixels.
return;
}
/* Our destination is one 256 pixel line. */
dst = line_buffer;
/* Clear our tileMask. */
memset(tile_mask,0x00, 0x100);
/*
Note that x is never tested for >255 since it automaticaly wraps
due to it's unsigned char declaration.
*/
/* Now, for 32 tiles... */
for (o=0; o<32;o++)
{
/* x = X scroll register, y = Y scroll register. */
y = REG9;
x = REG8;
/* Top 2 rows of screen not affected by horizontal scrolling. */
if ((REG0 & BIT6) && (line<=15))
{
x = 0;
}
x += o *8;
/* current_line = current line + scroll register modulated to stay in screen. 192 could be OK. */
if ((o >= 24) && (REG0 & BIT7))
{
/* Disable vertical scrolling for columns 24-31 */
current_line = ((line) % 224);
}
else
{
current_line = ((line+y) % 224);
}
/*
Now get VRAM index of the Tile/attrib in VDP memory.
8x8 Tile at Coord x, y = (x*64) + (y /8)
x * 64 because a line is 32 tiles, with 2 bytes for tile index and attribute.
y /8 because a tile is made of 8 lines.
*/
pos = ((current_line>>3)<<6) + o * 2;
/* get it's tile Index. */
currentTile = VRAM[ map_addr + pos++];
/* get it's attribute. */
attrib = VRAM[ map_addr + pos++];
if(attrib & BIT0)
{
currentTile |=0x100; // 9th tile index bit.
}
// line in tile converted to VRAM ind
if (attrib & BIT2)
{
// Verticaly flipped tile.
c = (7 - ((current_line & 7) )<<2) + (currentTile<<5);
}
else
{
c = ((current_line & 7)<<2) + (currentTile<<5);
}
// Four bytes are read into one 32bits variable. This avoid 3 memory access.
// Bits plan are like this in the variable (intel architecture):
// P3P2P1P0 which is inverse order or ram content. This is due to intel
// endianness
unsigned int *cst = (unsigned int *) &VRAM[c];
p = *cst;
c += 4;
// Draw 8 horizontals pixels.
switch ((attrib>>1) & 3)
{
case 0: // Tile not flipped
for ( i = 0; i<8; i++)
{
col_index = (p >>7)&1 | ((p >> 15)<<1)&2 | ((p >> 23)<<2)&4 | ((p >> 31)<<3);
if(attrib & BIT3) col_index|=0x10; // Then use sprite palete
dst[x] = colors[col_index];
if ((attrib & BIT4) && (col_index != 0x10) && (col_index !=0x0))
{
tile_mask[x] = 1;
}
x++;
p<<=1;
}
break;
case 1: // Tile flipped on x
for ( i = 0; i<8; i++)
{
col_index = (p&1) | ((p>>8) & 1)<<1 | ((p>>16) & 1 )<<2 | ((p >>24) &1)<<3;
if(attrib & BIT3) col_index|=0x10; // Then use sprite palete
dst[x] = colors[col_index];
if ((attrib & BIT4) && (col_index != 0x10) && (col_index !=0x0))
{
tile_mask[x] = 1;
}
x++;
p>>=1;
}
break;
case 2: // Tile flipped on y
for (int i=0; i<8;i++)
{
col_index = ((p>>7) &1)| ((p >> 15)&1)<<1 | ((p >> 23)&1)<<2 | ((p >> 31)&1)<<3;
if(attrib & BIT3) col_index|=0x10; // Then use sprite palete
dst[x] = colors[col_index];
if ((attrib & BIT4) && (col_index != 0x10) && (col_index !=0x0))
{
tile_mask[x] = 1;
}
x++;
p<<=1;
}
break;
case 3: // Tile flipped on x and y
for (int i=0; i<8;i++)
{
col_index = (p & 1) | ((p>>8) & 1)<<1 | ((p>>16) & 1)<<2 | ((p>>24) & 1)<<3;
if(attrib & BIT3) col_index|=0x10; // Then use sprite palete
dst[x] = colors[col_index];
if ((attrib & BIT4) && (col_index != 0x10) && (col_index !=0x0))
{
tile_mask[x] = 1;
}
x++;
p>>=1;
}
break;
} // switch attrib flip x/y
}
#ifdef DISPLAY_SPRITES
displaySpritesLine();
#endif
if (REG0 & BIT5) // Do not display (clear) leftmost column of the screen
{
unsigned short c = colors[(REG7 & 0xF)+16];
for (int u=0; u < 8; u++)
{
dst[u] = c;
}
}
// Copy buffer_line in screen line:
memcpy(scr,dst, 512);
}
/*-------------------------------------------------------------*/
/* This method will sprites on a given scanline on SDL_Surface */
/* The scanline is the line variable into VDP Class, which is */
/* the current line drawn. */
/*-------------------------------------------------------------*/
void VDP::displaySpritesLine()
{
unsigned char sprite_height = 8;
unsigned char displayedSprites;
unsigned short c;
unsigned char col_index;
int y;
unsigned int *cst;
unsigned int p;
bool double_size = false;
int x_spr[8];
int y_spr[8];
unsigned short ind_spr[8];
unsigned char line_spr[8];
unsigned char start_spr[8];
unsigned char width_spr[8];
if (REG1 & BIT1) // 8*16 sprites
{
sprite_height = 16;
}
displayedSprites = 0;
/* Note that if Bit0 and Bit1 of reg1 are set, sprites are 16*32. */
/* Earthworm jim uses this.*/
if (REG1 & BIT0)
{
sprite_height *= 2;
double_size = true;
}
// For all sprite information table
for (int j=0; j<64; j++)
{
y = (int)VRAM[sit_addr+j];
// y=208 mean stop displaying sprites.
if (y == 208)
{
break;
}
// Y position 0 means scanline 1.
y++;
if (y>240)
{
y-=256;
}
// Found one sprite to draw.
if ( (line>=y) && (line<(y + sprite_height)))
{
if (displayedSprites == 8)
{
vdp_status |= BIT6; /* Sprite overflow bit */
break;
}
ind_spr[displayedSprites] = VRAM[(sit_addr+129)+(j<<1)];
if (REG6 & BIT2) // 9th bit sprite nbr
{
ind_spr[displayedSprites] |= 0x100;
}
if (REG1 & BIT1)
{
ind_spr[displayedSprites] &=0x01FE;
}
y_spr[displayedSprites] = y;
line_spr[displayedSprites] = line - y;
if (double_size) line_spr[displayedSprites] = (line - y)>>1;
x_spr[displayedSprites] = VRAM[(sit_addr+128)+(j<<1)];
// Sprites moved 8 pixels left.
start_spr[displayedSprites] = 0; // First pixel in sprite line to draw.
if (REG0 & BIT3)
{
x_spr[displayedSprites]-=8;
if (x_spr[displayedSprites]<0)
{
start_spr[displayedSprites] = -x_spr[displayedSprites];
}
}
width_spr[displayedSprites] = 8; // Nbr of pixels in sprite line to draw.
if (x_spr[displayedSprites]>248)
{
width_spr[displayedSprites] = 256 - x_spr[displayedSprites];
}
displayedSprites++;
}
}
// Draw in reverse order.
for (int i= 0; i < 256; i++)
{
spr_col[i] = 0;
}
for (int r = displayedSprites-1; r >= 0; r--)
{
c = (line_spr[r]<<2) + (ind_spr[r]<<5);
cst = (unsigned int *) &VRAM[c];
p = *cst;
c += 4;
for (int i=start_spr[r]; i<width_spr[r];i++)
{
col_index = (p >>7)&1 | ((p >> 15)<<1)&2 | ((p >> 23)<<2)&4 | ((p >> 31)<<3);
col_index|=0x10; // Always use sprite palete
if(col_index != 0x10)
{
if (double_size)
{
if (tile_mask[x_spr[r]+i*2] == 0)
{
unsigned short u = x_spr[r]+(i*2);
line_buffer[u] = colors[col_index];
line_buffer[u+1] = colors[col_index];
if((spr_col[u] == 1) || (spr_col[u+1] == 1))
{
vdp_status |= BIT5; // Force collision to true
}
spr_col[u] = 1;
spr_col[u+1] = 1;
}
}
else
{
if (tile_mask[x_spr[r]+i] == 0)
{
unsigned short u = x_spr[r]+i;
line_buffer[u] = colors[col_index];
if(spr_col[u] == 1)
{
vdp_status |= BIT5; // Force collision to true
}
spr_col[u] = 1;
}
}
}
p<<=1;
}
}
}
/* Implemetntation of ImplementsSaveState. */
bool VDP::saveState( ofstream &ofs)
{
VDPSaveState vss;
/* Fill the structure. */
vss.map_addr = map_addr;
vss.sit_addr = sit_addr;
for (int i=0; i < VDP_REGISTER_NBR; i++) vss.regs[i] = regs[i];
vss.vdp_status = vdp_status;
vss.v_counter = v_counter;
vss.line = line;
vss.i_counter = i_counter;
vss.rd_data_port_buffer = rd_data_port_buffer;
vss.irq_line_pending = irq_line_pending;
vss.vsynch_irq_pending = vsynch_irq_pending;
vss.sms_irq = sms_irq;
vss.latch = latch;
vss.addr = addr;
vss.cmd_type = cmd_type;
vss.cmd_flag = cmd_flag;
/* Save VDP data. */
ofs.write((char *)&vss, sizeof(vss));
if (!ofs.good()) return false;
/* Save 16 Ko VRAM. */
ofs.write((char *)&VRAM[0], 0x4000);
if (!ofs.good()) return false;
/* Save 64 bytes CRAM. */
ofs.write((char *)&CRAM[0], 64);
if (!ofs.good()) return false;
return true;
}
bool VDP::loadState( ifstream &ifs)
{
VDPSaveState vss;
/* Load VDP data into structure */
ifs.read((char *)&vss, sizeof(vss));
if (!ifs.good()) return false;
map_addr = vss.map_addr ;
sit_addr = vss.sit_addr;
for (int i=0; i < VDP_REGISTER_NBR; i++) regs[i] = vss.regs[i];
vdp_status = vss.vdp_status;
v_counter = vss.v_counter;
line = vss.line;
i_counter = vss.i_counter;
rd_data_port_buffer = vss.rd_data_port_buffer;
irq_line_pending = vss.irq_line_pending;
vsynch_irq_pending = vss.vsynch_irq_pending;
sms_irq = vss.sms_irq;
latch = vss.latch;
addr = vss.addr;
cmd_type = vss.cmd_type;
cmd_flag = vss.cmd_flag;
/* Load 16 Ko VRAM. */
ifs.read((char *)&VRAM[0], 0x4000);
if (!ifs.good()) return false;
/* Load 64 bytes CRAM. */
ifs.read((char *)&CRAM[0], 64);
if (!ifs.good())
{
if (ifs.eof()) cout << "EOF!" << endl;
return false;
}
/* Now recompute colors that are usually computed on fly.*/
if (opt.MachineType == SMS)
{
for (int i=0; i < 0x1f; i++) colors[i] = colorSMS8BitsToColor16Bits(CRAM[i]);
}
if (opt.MachineType == GAMEGEAR)
{
unsigned short *CRAM16bits = (unsigned short *) CRAM;
for (int i=0; i < 0x1f; i++) colors[i] = colorGG12BitsToColor16Bits(CRAM16bits[i]);
}
return true;
}